1. Field of the Invention
The present invention relates to a hand operated chain block and, more particularly, to a hand operated chain block wherein a load sheave is rotationally driven by pulling a hand chain passing over a hand wheel, so as to wind up and down a load chain passing over the load sheave.
2. Description of the Prior Art
In general, a hand operated chain block of this type includes a load sheave supported between a pair of side plates via bearings; a hand wheel disposed at the outside of one side plate, so as to drive the load sheave through a drive shaft; and a mechanical brake interposed between the load sheave and the hand wheel. A hand wheel is rotationally driven by pulling a hand chain passing over the hand wheel, to cause the load sheave to be driven via the mechanical brake and the drive shaft, whereby the load chain is wound up and down to hoist up and down a load suspended from a hook.
Usually, this conventional type of chain block is provided with a wheel cover for covering the hand wheel and a brake cover for covering the mechanical brake, for the purpose of protecting the hand wheel and the mechanical brake from external environment and giving a good appearance to the chain block. In general, the wheel cover and the brake cover are separately fitted to the related side plate with fixture such as bolts. Japanese Published Patent No. Sho 51(1976)-40224 discloses that a flange extending outwardly in the same direction as the related side plate is formed along a marginal portion around the brake cover, so as to be sandwiched between the related side plate and the wheel cover and is fixedly held therebetween by tightening stay bolts for fitting the wheel cover.
However, for fitting the wheel cover and the brake cover fitted to the related side plate separately with fixture such as bolts, it takes time involving troublesome labor and also increased parts account is needed because of the fixture such as bolts being needed for each of the wheel cover and the brake cover.
In addition, the fixedly holding of the flange of the brake cover between the side plate and the wheel cover disadvantageously worsens the appearance, because the marginal portion of the brake cover is laid bare between the marginal portion around the side plate and the marginal portion around the wheel cover, when viewed from outside.